// SPDX-License-Identifier: MIT// OpenZeppelin Contracts v4.4.0 (utils/Address.sol)pragmasolidity ^0.8.0;/**
* @dev Collection of functions related to the address type
*/libraryAddress{
/**
* @dev Returns true if `account` is a contract.
*
* [IMPORTANT]
* ====
* It is unsafe to assume that an address for which this function returns
* false is an externally-owned account (EOA) and not a contract.
*
* Among others, `isContract` will return false for the following
* types of addresses:
*
* - an externally-owned account
* - a contract in construction
* - an address where a contract will be created
* - an address where a contract lived, but was destroyed
* ====
*/functionisContract(address account) internalviewreturns (bool) {
// This method relies on extcodesize, which returns 0 for contracts in// construction, since the code is only stored at the end of the// constructor execution.uint256 size;
assembly {
size :=extcodesize(account)
}
return size >0;
}
/**
* @dev Replacement for Solidity's `transfer`: sends `amount` wei to
* `recipient`, forwarding all available gas and reverting on errors.
*
* https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
* of certain opcodes, possibly making contracts go over the 2300 gas limit
* imposed by `transfer`, making them unable to receive funds via
* `transfer`. {sendValue} removes this limitation.
*
* https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
*
* IMPORTANT: because control is transferred to `recipient`, care must be
* taken to not create reentrancy vulnerabilities. Consider using
* {ReentrancyGuard} or the
* https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
*/functionsendValue(addresspayable recipient, uint256 amount) internal{
require(address(this).balance>= amount, "Address: insufficient balance");
(bool success, ) = recipient.call{value: amount}("");
require(success, "Address: unable to send value, recipient may have reverted");
}
/**
* @dev Performs a Solidity function call using a low level `call`. A
* plain `call` is an unsafe replacement for a function call: use this
* function instead.
*
* If `target` reverts with a revert reason, it is bubbled up by this
* function (like regular Solidity function calls).
*
* Returns the raw returned data. To convert to the expected return value,
* use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
*
* Requirements:
*
* - `target` must be a contract.
* - calling `target` with `data` must not revert.
*
* _Available since v3.1._
*/functionfunctionCall(address target, bytesmemory data) internalreturns (bytesmemory) {
return functionCall(target, data, "Address: low-level call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
* `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/functionfunctionCall(address target,
bytesmemory data,
stringmemory errorMessage
) internalreturns (bytesmemory) {
return functionCallWithValue(target, data, 0, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but also transferring `value` wei to `target`.
*
* Requirements:
*
* - the calling contract must have an ETH balance of at least `value`.
* - the called Solidity function must be `payable`.
*
* _Available since v3.1._
*/functionfunctionCallWithValue(address target,
bytesmemory data,
uint256 value
) internalreturns (bytesmemory) {
return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
}
/**
* @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
* with `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/functionfunctionCallWithValue(address target,
bytesmemory data,
uint256 value,
stringmemory errorMessage
) internalreturns (bytesmemory) {
require(address(this).balance>= value, "Address: insufficient balance for call");
require(isContract(target), "Address: call to non-contract");
(bool success, bytesmemory returndata) = target.call{value: value}(data);
return verifyCallResult(success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/functionfunctionStaticCall(address target, bytesmemory data) internalviewreturns (bytesmemory) {
return functionStaticCall(target, data, "Address: low-level static call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/functionfunctionStaticCall(address target,
bytesmemory data,
stringmemory errorMessage
) internalviewreturns (bytesmemory) {
require(isContract(target), "Address: static call to non-contract");
(bool success, bytesmemory returndata) = target.staticcall(data);
return verifyCallResult(success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.4._
*/functionfunctionDelegateCall(address target, bytesmemory data) internalreturns (bytesmemory) {
return functionDelegateCall(target, data, "Address: low-level delegate call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.4._
*/functionfunctionDelegateCall(address target,
bytesmemory data,
stringmemory errorMessage
) internalreturns (bytesmemory) {
require(isContract(target), "Address: delegate call to non-contract");
(bool success, bytesmemory returndata) = target.delegatecall(data);
return verifyCallResult(success, returndata, errorMessage);
}
/**
* @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
* revert reason using the provided one.
*
* _Available since v4.3._
*/functionverifyCallResult(bool success,
bytesmemory returndata,
stringmemory errorMessage
) internalpurereturns (bytesmemory) {
if (success) {
return returndata;
} else {
// Look for revert reason and bubble it up if presentif (returndata.length>0) {
// The easiest way to bubble the revert reason is using memory via assemblyassembly {
let returndata_size :=mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert(errorMessage);
}
}
}
}
Contract Source Code
File 2 of 29: Context.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts v4.4.0 (utils/Context.sol)pragmasolidity ^0.8.0;/**
* @dev Provides information about the current execution context, including the
* sender of the transaction and its data. While these are generally available
* via msg.sender and msg.data, they should not be accessed in such a direct
* manner, since when dealing with meta-transactions the account sending and
* paying for execution may not be the actual sender (as far as an application
* is concerned).
*
* This contract is only required for intermediate, library-like contracts.
*/abstractcontractContext{
function_msgSender() internalviewvirtualreturns (address) {
returnmsg.sender;
}
function_msgData() internalviewvirtualreturns (bytescalldata) {
returnmsg.data;
}
}
Contract Source Code
File 3 of 29: ContextMixin.sol
// SPDX-License-Identifier: MITpragmasolidity ^0.8.0;abstractcontractContextMixin{
functionmsgSender() internalviewreturns (addresspayable sender) {
if (msg.sender==address(this)) {
bytesmemory array =msg.data;
uint256 index =msg.data.length;
assembly {
// Load the 32 bytes word from memory with the address on the lower 20 bytes, and mask those.
sender :=and(
mload(add(array, index)),
0xffffffffffffffffffffffffffffffffffffffff
)
}
} else {
sender =payable(msg.sender);
}
return sender;
}
}
contractOwnableDelegateProxy{}
contractProxyRegistry{
mapping(address=> OwnableDelegateProxy) public proxies;
}
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts v4.4.0 (utils/cryptography/ECDSA.sol)pragmasolidity ^0.8.0;import"../Strings.sol";
/**
* @dev Elliptic Curve Digital Signature Algorithm (ECDSA) operations.
*
* These functions can be used to verify that a message was signed by the holder
* of the private keys of a given address.
*/libraryECDSA{
enumRecoverError {
NoError,
InvalidSignature,
InvalidSignatureLength,
InvalidSignatureS,
InvalidSignatureV
}
function_throwError(RecoverError error) privatepure{
if (error == RecoverError.NoError) {
return; // no error: do nothing
} elseif (error == RecoverError.InvalidSignature) {
revert("ECDSA: invalid signature");
} elseif (error == RecoverError.InvalidSignatureLength) {
revert("ECDSA: invalid signature length");
} elseif (error == RecoverError.InvalidSignatureS) {
revert("ECDSA: invalid signature 's' value");
} elseif (error == RecoverError.InvalidSignatureV) {
revert("ECDSA: invalid signature 'v' value");
}
}
/**
* @dev Returns the address that signed a hashed message (`hash`) with
* `signature` or error string. This address can then be used for verification purposes.
*
* The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
* this function rejects them by requiring the `s` value to be in the lower
* half order, and the `v` value to be either 27 or 28.
*
* IMPORTANT: `hash` _must_ be the result of a hash operation for the
* verification to be secure: it is possible to craft signatures that
* recover to arbitrary addresses for non-hashed data. A safe way to ensure
* this is by receiving a hash of the original message (which may otherwise
* be too long), and then calling {toEthSignedMessageHash} on it.
*
* Documentation for signature generation:
* - with https://web3js.readthedocs.io/en/v1.3.4/web3-eth-accounts.html#sign[Web3.js]
* - with https://docs.ethers.io/v5/api/signer/#Signer-signMessage[ethers]
*
* _Available since v4.3._
*/functiontryRecover(bytes32 hash, bytesmemory signature) internalpurereturns (address, RecoverError) {
// Check the signature length// - case 65: r,s,v signature (standard)// - case 64: r,vs signature (cf https://eips.ethereum.org/EIPS/eip-2098) _Available since v4.1._if (signature.length==65) {
bytes32 r;
bytes32 s;
uint8 v;
// ecrecover takes the signature parameters, and the only way to get them// currently is to use assembly.assembly {
r :=mload(add(signature, 0x20))
s :=mload(add(signature, 0x40))
v :=byte(0, mload(add(signature, 0x60)))
}
return tryRecover(hash, v, r, s);
} elseif (signature.length==64) {
bytes32 r;
bytes32 vs;
// ecrecover takes the signature parameters, and the only way to get them// currently is to use assembly.assembly {
r :=mload(add(signature, 0x20))
vs :=mload(add(signature, 0x40))
}
return tryRecover(hash, r, vs);
} else {
return (address(0), RecoverError.InvalidSignatureLength);
}
}
/**
* @dev Returns the address that signed a hashed message (`hash`) with
* `signature`. This address can then be used for verification purposes.
*
* The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
* this function rejects them by requiring the `s` value to be in the lower
* half order, and the `v` value to be either 27 or 28.
*
* IMPORTANT: `hash` _must_ be the result of a hash operation for the
* verification to be secure: it is possible to craft signatures that
* recover to arbitrary addresses for non-hashed data. A safe way to ensure
* this is by receiving a hash of the original message (which may otherwise
* be too long), and then calling {toEthSignedMessageHash} on it.
*/functionrecover(bytes32 hash, bytesmemory signature) internalpurereturns (address) {
(address recovered, RecoverError error) = tryRecover(hash, signature);
_throwError(error);
return recovered;
}
/**
* @dev Overload of {ECDSA-tryRecover} that receives the `r` and `vs` short-signature fields separately.
*
* See https://eips.ethereum.org/EIPS/eip-2098[EIP-2098 short signatures]
*
* _Available since v4.3._
*/functiontryRecover(bytes32 hash,
bytes32 r,
bytes32 vs
) internalpurereturns (address, RecoverError) {
bytes32 s;
uint8 v;
assembly {
s :=and(vs, 0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff)
v :=add(shr(255, vs), 27)
}
return tryRecover(hash, v, r, s);
}
/**
* @dev Overload of {ECDSA-recover} that receives the `r and `vs` short-signature fields separately.
*
* _Available since v4.2._
*/functionrecover(bytes32 hash,
bytes32 r,
bytes32 vs
) internalpurereturns (address) {
(address recovered, RecoverError error) = tryRecover(hash, r, vs);
_throwError(error);
return recovered;
}
/**
* @dev Overload of {ECDSA-tryRecover} that receives the `v`,
* `r` and `s` signature fields separately.
*
* _Available since v4.3._
*/functiontryRecover(bytes32 hash,
uint8 v,
bytes32 r,
bytes32 s
) internalpurereturns (address, RecoverError) {
// EIP-2 still allows signature malleability for ecrecover(). Remove this possibility and make the signature// unique. Appendix F in the Ethereum Yellow paper (https://ethereum.github.io/yellowpaper/paper.pdf), defines// the valid range for s in (301): 0 < s < secp256k1n ÷ 2 + 1, and for v in (302): v ∈ {27, 28}. Most// signatures from current libraries generate a unique signature with an s-value in the lower half order.//// If your library generates malleable signatures, such as s-values in the upper range, calculate a new s-value// with 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 - s1 and flip v from 27 to 28 or// vice versa. If your library also generates signatures with 0/1 for v instead 27/28, add 27 to v to accept// these malleable signatures as well.if (uint256(s) >0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0) {
return (address(0), RecoverError.InvalidSignatureS);
}
if (v !=27&& v !=28) {
return (address(0), RecoverError.InvalidSignatureV);
}
// If the signature is valid (and not malleable), return the signer addressaddress signer =ecrecover(hash, v, r, s);
if (signer ==address(0)) {
return (address(0), RecoverError.InvalidSignature);
}
return (signer, RecoverError.NoError);
}
/**
* @dev Overload of {ECDSA-recover} that receives the `v`,
* `r` and `s` signature fields separately.
*/functionrecover(bytes32 hash,
uint8 v,
bytes32 r,
bytes32 s
) internalpurereturns (address) {
(address recovered, RecoverError error) = tryRecover(hash, v, r, s);
_throwError(error);
return recovered;
}
/**
* @dev Returns an Ethereum Signed Message, created from a `hash`. This
* produces hash corresponding to the one signed with the
* https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]
* JSON-RPC method as part of EIP-191.
*
* See {recover}.
*/functiontoEthSignedMessageHash(bytes32 hash) internalpurereturns (bytes32) {
// 32 is the length in bytes of hash,// enforced by the type signature abovereturnkeccak256(abi.encodePacked("\x19Ethereum Signed Message:\n32", hash));
}
/**
* @dev Returns an Ethereum Signed Message, created from `s`. This
* produces hash corresponding to the one signed with the
* https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]
* JSON-RPC method as part of EIP-191.
*
* See {recover}.
*/functiontoEthSignedMessageHash(bytesmemory s) internalpurereturns (bytes32) {
returnkeccak256(abi.encodePacked("\x19Ethereum Signed Message:\n", Strings.toString(s.length), s));
}
/**
* @dev Returns an Ethereum Signed Typed Data, created from a
* `domainSeparator` and a `structHash`. This produces hash corresponding
* to the one signed with the
* https://eips.ethereum.org/EIPS/eip-712[`eth_signTypedData`]
* JSON-RPC method as part of EIP-712.
*
* See {recover}.
*/functiontoTypedDataHash(bytes32 domainSeparator, bytes32 structHash) internalpurereturns (bytes32) {
returnkeccak256(abi.encodePacked("\x19\x01", domainSeparator, structHash));
}
}
Contract Source Code
File 6 of 29: EIP712Base.sol
// SPDX-License-Identifier: MITpragmasolidity ^0.8.0;import {Initializable} from"./Initializable.sol";
contractEIP712BaseisInitializable{
structEIP712Domain {
string name;
string version;
address verifyingContract;
bytes32 salt;
}
stringpublicconstant ERC712_VERSION ="1";
bytes32internalconstant EIP712_DOMAIN_TYPEHASH =keccak256(
bytes(
"EIP712Domain(string name,string version,address verifyingContract,bytes32 salt)"
)
);
bytes32internal domainSeperator;
// supposed to be called once while initializing.// one of the contracts that inherits this contract follows proxy pattern// so it is not possible to do this in a constructorfunction_initializeEIP712(stringmemory name) internalinitializer{
_setDomainSeperator(name);
}
function_setDomainSeperator(stringmemory name) internal{
domainSeperator =keccak256(
abi.encode(
EIP712_DOMAIN_TYPEHASH,
keccak256(bytes(name)),
keccak256(bytes(ERC712_VERSION)),
address(this),
bytes32(getChainId())
)
);
}
functiongetDomainSeperator() publicviewreturns (bytes32) {
return domainSeperator;
}
functiongetChainId() publicviewreturns (uint256) {
uint256 id;
assembly {
id :=chainid()
}
return id;
}
/**
* Accept message hash and returns hash message in EIP712 compatible form
* So that it can be used to recover signer from signature signed using EIP712 formatted data
* https://eips.ethereum.org/EIPS/eip-712
* "\\x19" makes the encoding deterministic
* "\\x01" is the version byte to make it compatible to EIP-191
*/functiontoTypedMessageHash(bytes32 messageHash)
internalviewreturns (bytes32)
{
returnkeccak256(
abi.encodePacked("\x19\x01", getDomainSeperator(), messageHash)
);
}
}
Contract Source Code
File 7 of 29: ERC165.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts v4.4.0 (utils/introspection/ERC165.sol)pragmasolidity ^0.8.0;import"./IERC165.sol";
/**
* @dev Implementation of the {IERC165} interface.
*
* Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
* for the additional interface id that will be supported. For example:
*
* ```solidity
* function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
* return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
* }
* ```
*
* Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
*/abstractcontractERC165isIERC165{
/**
* @dev See {IERC165-supportsInterface}.
*/functionsupportsInterface(bytes4 interfaceId) publicviewvirtualoverridereturns (bool) {
return interfaceId ==type(IERC165).interfaceId;
}
}
Contract Source Code
File 8 of 29: ERC20.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts v4.4.0 (token/ERC20/ERC20.sol)pragmasolidity ^0.8.0;import"./IERC20.sol";
import"./extensions/IERC20Metadata.sol";
import"../../utils/Context.sol";
/**
* @dev Implementation of the {IERC20} interface.
*
* This implementation is agnostic to the way tokens are created. This means
* that a supply mechanism has to be added in a derived contract using {_mint}.
* For a generic mechanism see {ERC20PresetMinterPauser}.
*
* TIP: For a detailed writeup see our guide
* https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
* to implement supply mechanisms].
*
* We have followed general OpenZeppelin Contracts guidelines: functions revert
* instead returning `false` on failure. This behavior is nonetheless
* conventional and does not conflict with the expectations of ERC20
* applications.
*
* Additionally, an {Approval} event is emitted on calls to {transferFrom}.
* This allows applications to reconstruct the allowance for all accounts just
* by listening to said events. Other implementations of the EIP may not emit
* these events, as it isn't required by the specification.
*
* Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
* functions have been added to mitigate the well-known issues around setting
* allowances. See {IERC20-approve}.
*/contractERC20isContext, IERC20, IERC20Metadata{
mapping(address=>uint256) private _balances;
mapping(address=>mapping(address=>uint256)) private _allowances;
uint256private _totalSupply;
stringprivate _name;
stringprivate _symbol;
/**
* @dev Sets the values for {name} and {symbol}.
*
* The default value of {decimals} is 18. To select a different value for
* {decimals} you should overload it.
*
* All two of these values are immutable: they can only be set once during
* construction.
*/constructor(stringmemory name_, stringmemory symbol_) {
_name = name_;
_symbol = symbol_;
}
/**
* @dev Returns the name of the token.
*/functionname() publicviewvirtualoverridereturns (stringmemory) {
return _name;
}
/**
* @dev Returns the symbol of the token, usually a shorter version of the
* name.
*/functionsymbol() publicviewvirtualoverridereturns (stringmemory) {
return _symbol;
}
/**
* @dev Returns the number of decimals used to get its user representation.
* For example, if `decimals` equals `2`, a balance of `505` tokens should
* be displayed to a user as `5.05` (`505 / 10 ** 2`).
*
* Tokens usually opt for a value of 18, imitating the relationship between
* Ether and Wei. This is the value {ERC20} uses, unless this function is
* overridden;
*
* NOTE: This information is only used for _display_ purposes: it in
* no way affects any of the arithmetic of the contract, including
* {IERC20-balanceOf} and {IERC20-transfer}.
*/functiondecimals() publicviewvirtualoverridereturns (uint8) {
return18;
}
/**
* @dev See {IERC20-totalSupply}.
*/functiontotalSupply() publicviewvirtualoverridereturns (uint256) {
return _totalSupply;
}
/**
* @dev See {IERC20-balanceOf}.
*/functionbalanceOf(address account) publicviewvirtualoverridereturns (uint256) {
return _balances[account];
}
/**
* @dev See {IERC20-transfer}.
*
* Requirements:
*
* - `recipient` cannot be the zero address.
* - the caller must have a balance of at least `amount`.
*/functiontransfer(address recipient, uint256 amount) publicvirtualoverridereturns (bool) {
_transfer(_msgSender(), recipient, amount);
returntrue;
}
/**
* @dev See {IERC20-allowance}.
*/functionallowance(address owner, address spender) publicviewvirtualoverridereturns (uint256) {
return _allowances[owner][spender];
}
/**
* @dev See {IERC20-approve}.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/functionapprove(address spender, uint256 amount) publicvirtualoverridereturns (bool) {
_approve(_msgSender(), spender, amount);
returntrue;
}
/**
* @dev See {IERC20-transferFrom}.
*
* Emits an {Approval} event indicating the updated allowance. This is not
* required by the EIP. See the note at the beginning of {ERC20}.
*
* Requirements:
*
* - `sender` and `recipient` cannot be the zero address.
* - `sender` must have a balance of at least `amount`.
* - the caller must have allowance for ``sender``'s tokens of at least
* `amount`.
*/functiontransferFrom(address sender,
address recipient,
uint256 amount
) publicvirtualoverridereturns (bool) {
_transfer(sender, recipient, amount);
uint256 currentAllowance = _allowances[sender][_msgSender()];
require(currentAllowance >= amount, "ERC20: transfer amount exceeds allowance");
unchecked {
_approve(sender, _msgSender(), currentAllowance - amount);
}
returntrue;
}
/**
* @dev Atomically increases the allowance granted to `spender` by the caller.
*
* This is an alternative to {approve} that can be used as a mitigation for
* problems described in {IERC20-approve}.
*
* Emits an {Approval} event indicating the updated allowance.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/functionincreaseAllowance(address spender, uint256 addedValue) publicvirtualreturns (bool) {
_approve(_msgSender(), spender, _allowances[_msgSender()][spender] + addedValue);
returntrue;
}
/**
* @dev Atomically decreases the allowance granted to `spender` by the caller.
*
* This is an alternative to {approve} that can be used as a mitigation for
* problems described in {IERC20-approve}.
*
* Emits an {Approval} event indicating the updated allowance.
*
* Requirements:
*
* - `spender` cannot be the zero address.
* - `spender` must have allowance for the caller of at least
* `subtractedValue`.
*/functiondecreaseAllowance(address spender, uint256 subtractedValue) publicvirtualreturns (bool) {
uint256 currentAllowance = _allowances[_msgSender()][spender];
require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
unchecked {
_approve(_msgSender(), spender, currentAllowance - subtractedValue);
}
returntrue;
}
/**
* @dev Moves `amount` of tokens from `sender` to `recipient`.
*
* This internal function is equivalent to {transfer}, and can be used to
* e.g. implement automatic token fees, slashing mechanisms, etc.
*
* Emits a {Transfer} event.
*
* Requirements:
*
* - `sender` cannot be the zero address.
* - `recipient` cannot be the zero address.
* - `sender` must have a balance of at least `amount`.
*/function_transfer(address sender,
address recipient,
uint256 amount
) internalvirtual{
require(sender !=address(0), "ERC20: transfer from the zero address");
require(recipient !=address(0), "ERC20: transfer to the zero address");
_beforeTokenTransfer(sender, recipient, amount);
uint256 senderBalance = _balances[sender];
require(senderBalance >= amount, "ERC20: transfer amount exceeds balance");
unchecked {
_balances[sender] = senderBalance - amount;
}
_balances[recipient] += amount;
emit Transfer(sender, recipient, amount);
_afterTokenTransfer(sender, recipient, amount);
}
/** @dev Creates `amount` tokens and assigns them to `account`, increasing
* the total supply.
*
* Emits a {Transfer} event with `from` set to the zero address.
*
* Requirements:
*
* - `account` cannot be the zero address.
*/function_mint(address account, uint256 amount) internalvirtual{
require(account !=address(0), "ERC20: mint to the zero address");
_beforeTokenTransfer(address(0), account, amount);
_totalSupply += amount;
_balances[account] += amount;
emit Transfer(address(0), account, amount);
_afterTokenTransfer(address(0), account, amount);
}
/**
* @dev Destroys `amount` tokens from `account`, reducing the
* total supply.
*
* Emits a {Transfer} event with `to` set to the zero address.
*
* Requirements:
*
* - `account` cannot be the zero address.
* - `account` must have at least `amount` tokens.
*/function_burn(address account, uint256 amount) internalvirtual{
require(account !=address(0), "ERC20: burn from the zero address");
_beforeTokenTransfer(account, address(0), amount);
uint256 accountBalance = _balances[account];
require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
unchecked {
_balances[account] = accountBalance - amount;
}
_totalSupply -= amount;
emit Transfer(account, address(0), amount);
_afterTokenTransfer(account, address(0), amount);
}
/**
* @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
*
* This internal function is equivalent to `approve`, and can be used to
* e.g. set automatic allowances for certain subsystems, etc.
*
* Emits an {Approval} event.
*
* Requirements:
*
* - `owner` cannot be the zero address.
* - `spender` cannot be the zero address.
*/function_approve(address owner,
address spender,
uint256 amount
) internalvirtual{
require(owner !=address(0), "ERC20: approve from the zero address");
require(spender !=address(0), "ERC20: approve to the zero address");
_allowances[owner][spender] = amount;
emit Approval(owner, spender, amount);
}
/**
* @dev Hook that is called before any transfer of tokens. This includes
* minting and burning.
*
* Calling conditions:
*
* - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
* will be transferred to `to`.
* - when `from` is zero, `amount` tokens will be minted for `to`.
* - when `to` is zero, `amount` of ``from``'s tokens will be burned.
* - `from` and `to` are never both zero.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
*/function_beforeTokenTransfer(addressfrom,
address to,
uint256 amount
) internalvirtual{}
/**
* @dev Hook that is called after any transfer of tokens. This includes
* minting and burning.
*
* Calling conditions:
*
* - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
* has been transferred to `to`.
* - when `from` is zero, `amount` tokens have been minted for `to`.
* - when `to` is zero, `amount` of ``from``'s tokens have been burned.
* - `from` and `to` are never both zero.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
*/function_afterTokenTransfer(addressfrom,
address to,
uint256 amount
) internalvirtual{}
}
Contract Source Code
File 9 of 29: ERC20Burnable.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts v4.4.0 (token/ERC20/extensions/ERC20Burnable.sol)pragmasolidity ^0.8.0;import"../ERC20.sol";
import"../../../utils/Context.sol";
/**
* @dev Extension of {ERC20} that allows token holders to destroy both their own
* tokens and those that they have an allowance for, in a way that can be
* recognized off-chain (via event analysis).
*/abstractcontractERC20BurnableisContext, ERC20{
/**
* @dev Destroys `amount` tokens from the caller.
*
* See {ERC20-_burn}.
*/functionburn(uint256 amount) publicvirtual{
_burn(_msgSender(), amount);
}
/**
* @dev Destroys `amount` tokens from `account`, deducting from the caller's
* allowance.
*
* See {ERC20-_burn} and {ERC20-allowance}.
*
* Requirements:
*
* - the caller must have allowance for ``accounts``'s tokens of at least
* `amount`.
*/functionburnFrom(address account, uint256 amount) publicvirtual{
uint256 currentAllowance = allowance(account, _msgSender());
require(currentAllowance >= amount, "ERC20: burn amount exceeds allowance");
unchecked {
_approve(account, _msgSender(), currentAllowance - amount);
}
_burn(account, amount);
}
}
Contract Source Code
File 10 of 29: ERC721AMultiMint.sol
// SPDX-License-Identifier: MIT// Creator: Chiru Labspragmasolidity ^0.8.4;import'@openzeppelin/contracts/token/ERC721/IERC721.sol';
import'@openzeppelin/contracts/token/ERC721/IERC721Receiver.sol';
import'@openzeppelin/contracts/token/ERC721/extensions/IERC721Metadata.sol';
import'@openzeppelin/contracts/utils/Address.sol';
import'@openzeppelin/contracts/utils/Context.sol';
import'@openzeppelin/contracts/utils/Strings.sol';
import'@openzeppelin/contracts/utils/introspection/ERC165.sol';
errorApprovalCallerNotOwnerNorApproved();
errorApprovalQueryForNonexistentToken();
errorApproveToCaller();
errorApprovalToCurrentOwner();
errorBalanceQueryForZeroAddress();
errorMintToZeroAddress();
errorMintZeroQuantity();
errorOwnerQueryForNonexistentToken();
errorTransferCallerNotOwnerNorApproved();
errorTransferFromIncorrectOwner();
errorTransferToNonERC721ReceiverImplementer();
errorTransferToZeroAddress();
errorURIQueryForNonexistentToken();
errorSetTimestampsDuplicates();
errorSetTimestampsIncorrectOwner();
errorInvalidQueryRange();
/**
* @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including
* the Metadata extension. Built to optimize for lower gas during batch mints.
*
* Assumes serials are sequentially minted starting at _startTokenId() (defaults to 0, e.g. 0, 1, 2, 3..).
*
* Assumes that an owner cannot have more than 2**64 - 1 (max value of uint64) of supply.
*
* Assumes that the maximum token id cannot exceed 2**256 - 1 (max value of uint256).
*/contractERC721AMultiMintisContext, ERC165, IERC721, IERC721Metadata{
usingAddressforaddress;
usingStringsforuint256;
uint256privateconstant MAX_RANGE =20;
// Compiler will pack this into a single 256bit word.structTokenOwnership {
// The address of the owner.address addr;
// Keeps track of the start time of ownership with minimal overhead for tokenomics.uint64 startTimestamp;
// Whether the token has been burned.bool burned;
}
// Compiler will pack this into a single 256bit word.structAddressData {
// Realistically, 2**64-1 is more than enough.uint24 balance;
// Keeps track of mint count with minimal overhead for tokenomics.uint24 numberMinted;
// Keeps track of burn count with minimal overhead for tokenomics.uint24 numberBurned;
// Keeps track of whitelist mint count with minimal overhead for tokenomics.uint8 numberWhitelistMinted;
// For miscellaneous variable(s) pertaining to the address// If there are multiple variables, please pack them into a uint64.uint176 aux;
}
// Token namestringprivate _name;
// Token symbolstringprivate _symbol;
// Mapping from token ID to ownership details// An empty struct value does not necessarily mean the token is unowned. See _ownershipOf implementation for details.mapping(uint256=> TokenOwnership) internal _ownerships;
// Mapping owner address to address datamapping(address=> AddressData) private _addressData;
// Mapping from token ID to approved addressmapping(uint256=>address) private _tokenApprovals;
// Mapping from owner to operator approvalsmapping(address=>mapping(address=>bool)) private _operatorApprovals;
// The tokenId of the next token to be minted.uint32internal _currentIndex;
// The number of tokens burned.uint32internal _burnCounter;
constructor(stringmemory name_, stringmemory symbol_) {
_name = name_;
_symbol = symbol_;
_currentIndex =uint32(_startTokenId());
}
/**
* To change the starting tokenId, please override this function.
*/function_startTokenId() internalviewvirtualreturns (uint256) {
return0;
}
/**
* @dev Burned tokens are calculated here, use _totalMinted() if you want to count just minted tokens.
*/functiontotalSupply() publicviewreturns (uint256) {
// Counter underflow is impossible as _burnCounter cannot be incremented// more than _currentIndex - _startTokenId() timesunchecked {
return _currentIndex - _burnCounter - _startTokenId();
}
}
/**
* Returns the total amount of tokens minted in the contract.
*/function_totalMinted() internalviewreturns (uint256) {
// Counter underflow is impossible as _currentIndex does not decrement,// and it is initialized to _startTokenId()unchecked {
return _currentIndex - _startTokenId();
}
}
/**
* @dev See {IERC165-supportsInterface}.
*/functionsupportsInterface(bytes4 interfaceId) publicviewvirtualoverride(ERC165, IERC165) returns (bool) {
return
interfaceId ==type(IERC721).interfaceId||
interfaceId ==type(IERC721Metadata).interfaceId||super.supportsInterface(interfaceId);
}
/**
* @dev See {IERC721-balanceOf}.
*/functionbalanceOf(address owner) publicviewoverridereturns (uint256) {
if (owner ==address(0)) revert BalanceQueryForZeroAddress();
returnuint256(_addressData[owner].balance);
}
/**
* Returns the number of tokens minted by `owner`.
*/function_numberMinted(address owner) internalviewreturns (uint256) {
returnuint256(_addressData[owner].numberMinted);
}
/**
* Returns the number of tokens burned by or on behalf of `owner`.
*/function_numberBurned(address owner) internalviewreturns (uint256) {
returnuint256(_addressData[owner].numberBurned);
}
function_numberWhitelistMinted(address owner) internalviewreturns (uint8) {
return _addressData[owner].numberWhitelistMinted;
}
function_setNumberWhitelistMinted(address owner, uint8 number) internal{
_addressData[owner].numberWhitelistMinted = number;
}
/**
* Returns the auxillary data for `owner`. (e.g. number of whitelist mint slots used).
*/function_getAux(address owner) internalviewreturns (uint176) {
return _addressData[owner].aux;
}
/**
* Sets the auxillary data for `owner`. (e.g. number of whitelist mint slots used).
* If there are multiple variables, please pack them into a uint64.
*/function_setAux(address owner, uint176 aux) internal{
_addressData[owner].aux = aux;
}
/**
* Gas spent here starts off proportional to the maximum mint batch size.
* It gradually moves to O(1) as tokens get transferred around in the collection over time.
*/function_ownershipOf(uint256 tokenId) internalviewreturns (TokenOwnership memory) {
uint256 curr = tokenId;
unchecked {
if (_startTokenId() <= curr && curr < _currentIndex) {
TokenOwnership memory ownership = _ownerships[curr];
if (!ownership.burned) {
if (ownership.addr !=address(0)) {
return ownership;
}
// Invariant:// There will always be an ownership that has an address and is not burned// before an ownership that does not have an address and is not burned.// Hence, curr will not underflow.while (true) {
curr--;
ownership = _ownerships[curr];
if (ownership.addr !=address(0)) {
return ownership;
}
}
}
}
}
revert OwnerQueryForNonexistentToken();
}
function_setTimestampOf(uint256 tokenId, uint64 timestamp) internalreturns (uint64) {
TokenOwnership memory prevOwnership = _ownershipOf(tokenId);
address owner = prevOwnership.addr;
unchecked {
TokenOwnership storage currSlot = _ownerships[tokenId];
currSlot.addr = owner;
currSlot.startTimestamp = timestamp;
// If the ownership slot of tokenId+1 is not explicitly set, that means the setTimestampOf initiator owns it.// Set the slot of tokenId+1 explicitly in storage to maintain correctness for timestampOf(tokenId+1) calls.uint256 nextTokenId = tokenId +1;
TokenOwnership storage nextSlot = _ownerships[nextTokenId];
if (nextSlot.addr ==address(0)) {
// This will suffice for checking _exists(nextTokenId),// as a burned slot cannot contain the zero address.if (nextTokenId != _currentIndex) {
nextSlot.addr = owner;
nextSlot.startTimestamp = prevOwnership.startTimestamp;
}
}
}
return prevOwnership.startTimestamp;
}
function_setTimestampsOf(address owner, uint256[] calldata tokenIds, uint64 timestamp) internalreturns (uint64[] memory prevTimestamps) {
unchecked {
uint256 length = tokenIds.length;
prevTimestamps =newuint64[](length);
uint256 prevTokenId =0;
uint256 i =0;
while (i < length) {
uint256 tokenId = tokenIds[i];
if (prevTokenId >= tokenId) revert SetTimestampsDuplicates();
TokenOwnership memory prevOwnership = _ownershipOf(tokenId);
prevTimestamps[i++] = prevOwnership.startTimestamp;
if (prevOwnership.addr != owner) revert SetTimestampsIncorrectOwner();
TokenOwnership storage currSlot = _ownerships[tokenId];
currSlot.addr = owner;
currSlot.startTimestamp = timestamp;
for (;;) {
uint256 nextTokenId = tokenId +1;
TokenOwnership storage nextSlot = _ownerships[nextTokenId];
// If the nextslot is not the zero address then nextTokenId// is not part of a token range from ownerif (nextSlot.addr !=address(0)) {
break;
}
// This will suffice for checking _exists(nextTokenId),// as a burned slot cannot contain the zero address.if (nextTokenId == _currentIndex) {
break;
}
// nextTokenId is part of a token range, check if// nextTokenId is also the next in the tokenIds array// if not, then the timestamp for the tokens after// tokenId needs to be preservedif (i >= length || tokenIds[i] != nextTokenId) {
nextSlot.addr = owner;
nextSlot.startTimestamp = prevOwnership.startTimestamp;
break;
}
// At this point nextTokenId is also next in the tokenIds// array, no need to change storage, just return the token// range timestamp and continue with the next tokenId
prevTimestamps[i++] = prevOwnership.startTimestamp;
tokenId = nextTokenId;
}
prevTokenId = tokenId;
}
}
}
/**
* @dev See {IERC721-ownerOf}.
*/functionownerOf(uint256 tokenId) publicviewoverridereturns (address) {
return _ownershipOf(tokenId).addr;
}
/**
* @dev See {IERC721Metadata-name}.
*/functionname() publicviewvirtualoverridereturns (stringmemory) {
return _name;
}
/**
* @dev See {IERC721Metadata-symbol}.
*/functionsymbol() publicviewvirtualoverridereturns (stringmemory) {
return _symbol;
}
/**
* @dev See {IERC721Metadata-tokenURI}.
*/functiontokenURI(uint256 tokenId) publicviewvirtualoverridereturns (stringmemory) {
if (!_exists(tokenId)) revert URIQueryForNonexistentToken();
stringmemory baseURI = _baseURI();
returnbytes(baseURI).length!=0 ? string(abi.encodePacked(baseURI, tokenId.toString())) : '';
}
/**
* @dev Base URI for computing {tokenURI}. If set, the resulting URI for each
* token will be the concatenation of the `baseURI` and the `tokenId`. Empty
* by default, can be overriden in child contracts.
*/function_baseURI() internalviewvirtualreturns (stringmemory) {
return'';
}
/**
* @dev See {IERC721-approve}.
*/functionapprove(address to, uint256 tokenId) publicoverride{
address owner = ERC721AMultiMint.ownerOf(tokenId);
if (to == owner) revert ApprovalToCurrentOwner();
if (_msgSender() != owner &&!isApprovedForAll(owner, _msgSender())) {
revert ApprovalCallerNotOwnerNorApproved();
}
_approve(to, tokenId, owner);
}
/**
* @dev See {IERC721-getApproved}.
*/functiongetApproved(uint256 tokenId) publicviewoverridereturns (address) {
if (!_exists(tokenId)) revert ApprovalQueryForNonexistentToken();
return _tokenApprovals[tokenId];
}
/**
* @dev See {IERC721-setApprovalForAll}.
*/functionsetApprovalForAll(address operator, bool approved) publicvirtualoverride{
if (operator == _msgSender()) revert ApproveToCaller();
_operatorApprovals[_msgSender()][operator] = approved;
emit ApprovalForAll(_msgSender(), operator, approved);
}
/**
* @dev See {IERC721-isApprovedForAll}.
*/functionisApprovedForAll(address owner, address operator) publicviewvirtualoverridereturns (bool) {
return _operatorApprovals[owner][operator];
}
/**
* @dev See {IERC721-transferFrom}.
*/functiontransferFrom(addressfrom,
address to,
uint256 tokenId
) publicvirtualoverride{
_transfer(from, to, tokenId);
}
/**
* @dev See {IERC721-safeTransferFrom}.
*/functionsafeTransferFrom(addressfrom,
address to,
uint256 tokenId
) publicvirtualoverride{
safeTransferFrom(from, to, tokenId, '');
}
/**
* @dev See {IERC721-safeTransferFrom}.
*/functionsafeTransferFrom(addressfrom,
address to,
uint256 tokenId,
bytesmemory _data
) publicvirtualoverride{
_transfer(from, to, tokenId);
if (to.isContract() &&!_checkContractOnERC721Received(from, to, tokenId, _data)) {
revert TransferToNonERC721ReceiverImplementer();
}
}
/**
* @dev Returns whether `tokenId` exists.
*
* Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}.
*
* Tokens start existing when they are minted (`_mint`),
*/function_exists(uint256 tokenId) internalviewreturns (bool) {
return _startTokenId() <= tokenId && tokenId < _currentIndex &&!_ownerships[tokenId].burned;
}
function_safeMint(address to, uint256 quantity) internal{
_safeMint(to, quantity, '');
}
/**
* @dev Safely mints `quantity` tokens and transfers them to `to`.
*
* Requirements:
*
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called for each safe transfer.
* - `quantity` must be greater than 0.
*
* Emits a {Transfer} event.
*/function_safeMint(address to,
uint256 quantity,
bytesmemory _data
) internal{
_mint(to, quantity, _data, true);
}
/**
* @dev Mints `quantity` tokens and transfers them to `to`.
*
* Requirements:
*
* - `to` cannot be the zero address.
* - `quantity` must be greater than 0.
*
* Emits a {Transfer} event.
*/function_mint(address to,
uint256 quantity,
bytesmemory _data,
bool safe
) internal{
uint256 startTokenId = _currentIndex;
if (to ==address(0)) revert MintToZeroAddress();
if (quantity ==0) revert MintZeroQuantity();
_beforeTokenTransfers(address(0), to, startTokenId, quantity);
// Overflows are incredibly unrealistic.// balance or numberMinted overflow if current value of either + quantity > 1.8e19 (2**64) - 1// updatedIndex overflows if _currentIndex + quantity > 1.2e77 (2**256) - 1unchecked {
_addressData[to].balance+=uint24(quantity);
_addressData[to].numberMinted +=uint24(quantity);
uint256 updatedIndex = startTokenId;
uint256 end = updatedIndex + quantity;
uint256 writeCount = (quantity + MAX_RANGE -1) / MAX_RANGE;
uint256 writeStep = quantity / writeCount;
uint256 writePosition = startTokenId;
for (uint256 i =0; i < writeCount; ++i) {
_ownerships[writePosition].addr = to;
_ownerships[writePosition].startTimestamp =uint64(block.timestamp);
writePosition += writeStep;
}
if (safe && to.isContract()) {
do {
emit Transfer(address(0), to, updatedIndex);
if (!_checkContractOnERC721Received(address(0), to, updatedIndex++, _data)) {
revert TransferToNonERC721ReceiverImplementer();
}
} while (updatedIndex != end);
// Reentrancy protectionif (_currentIndex != startTokenId) revert();
} else {
do {
emit Transfer(address(0), to, updatedIndex++);
} while (updatedIndex != end);
}
_currentIndex =uint32(updatedIndex);
}
_afterTokenTransfers(address(0), to, startTokenId, quantity);
}
/**
* @dev Transfers `tokenId` from `from` to `to`.
*
* Requirements:
*
* - `to` cannot be the zero address.
* - `tokenId` token must be owned by `from`.
*
* Emits a {Transfer} event.
*/function_transfer(addressfrom,
address to,
uint256 tokenId
) private{
TokenOwnership memory prevOwnership = _ownershipOf(tokenId);
if (prevOwnership.addr !=from) revert TransferFromIncorrectOwner();
bool isApprovedOrOwner = (_msgSender() ==from||
isApprovedForAll(from, _msgSender()) ||
getApproved(tokenId) == _msgSender());
if (!isApprovedOrOwner) revert TransferCallerNotOwnerNorApproved();
if (to ==address(0)) revert TransferToZeroAddress();
_beforeTokenTransfers(from, to, tokenId, 1);
// Clear approvals from the previous owner
_approve(address(0), tokenId, from);
// Underflow of the sender's balance is impossible because we check for// ownership above and the recipient's balance can't realistically overflow.// Counter overflow is incredibly unrealistic as tokenId would have to be 2**256.unchecked {
_addressData[from].balance-=1;
_addressData[to].balance+=1;
TokenOwnership storage currSlot = _ownerships[tokenId];
currSlot.addr = to;
currSlot.startTimestamp =uint64(block.timestamp);
// If the ownership slot of tokenId+1 is not explicitly set, that means the transfer initiator owns it.// Set the slot of tokenId+1 explicitly in storage to maintain correctness for ownerOf(tokenId+1) calls.uint256 nextTokenId = tokenId +1;
TokenOwnership storage nextSlot = _ownerships[nextTokenId];
if (nextSlot.addr ==address(0)) {
// This will suffice for checking _exists(nextTokenId),// as a burned slot cannot contain the zero address.if (nextTokenId != _currentIndex) {
nextSlot.addr =from;
nextSlot.startTimestamp = prevOwnership.startTimestamp;
}
}
}
emit Transfer(from, to, tokenId);
_afterTokenTransfers(from, to, tokenId, 1);
}
/**
* @dev This is equivalent to _burn(tokenId, false)
*/function_burn(uint256 tokenId) internalvirtual{
_burn(tokenId, false);
}
/**
* @dev Destroys `tokenId`.
* The approval is cleared when the token is burned.
*
* Requirements:
*
* - `tokenId` must exist.
*
* Emits a {Transfer} event.
*/function_burn(uint256 tokenId, bool approvalCheck) internalvirtual{
TokenOwnership memory prevOwnership = _ownershipOf(tokenId);
addressfrom= prevOwnership.addr;
if (approvalCheck) {
bool isApprovedOrOwner = (_msgSender() ==from||
isApprovedForAll(from, _msgSender()) ||
getApproved(tokenId) == _msgSender());
if (!isApprovedOrOwner) revert TransferCallerNotOwnerNorApproved();
}
_beforeTokenTransfers(from, address(0), tokenId, 1);
// Clear approvals from the previous owner
_approve(address(0), tokenId, from);
// Underflow of the sender's balance is impossible because we check for// ownership above and the recipient's balance can't realistically overflow.// Counter overflow is incredibly unrealistic as tokenId would have to be 2**256.unchecked {
AddressData storage addressData = _addressData[from];
addressData.balance-=1;
addressData.numberBurned +=1;
// Keep track of who burned the token, and the timestamp of burning.
TokenOwnership storage currSlot = _ownerships[tokenId];
currSlot.addr =from;
currSlot.startTimestamp =uint64(block.timestamp);
currSlot.burned =true;
// If the ownership slot of tokenId+1 is not explicitly set, that means the burn initiator owns it.// Set the slot of tokenId+1 explicitly in storage to maintain correctness for ownerOf(tokenId+1) calls.uint256 nextTokenId = tokenId +1;
TokenOwnership storage nextSlot = _ownerships[nextTokenId];
if (nextSlot.addr ==address(0)) {
// This will suffice for checking _exists(nextTokenId),// as a burned slot cannot contain the zero address.if (nextTokenId != _currentIndex) {
nextSlot.addr =from;
nextSlot.startTimestamp = prevOwnership.startTimestamp;
}
}
}
emit Transfer(from, address(0), tokenId);
_afterTokenTransfers(from, address(0), tokenId, 1);
// Overflow not possible, as _burnCounter cannot be exceed _currentIndex times.unchecked {
_burnCounter++;
}
}
/**
* @dev Approve `to` to operate on `tokenId`
*
* Emits a {Approval} event.
*/function_approve(address to,
uint256 tokenId,
address owner
) private{
_tokenApprovals[tokenId] = to;
emit Approval(owner, to, tokenId);
}
/**
* @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target contract.
*
* @param from address representing the previous owner of the given token ID
* @param to target address that will receive the tokens
* @param tokenId uint256 ID of the token to be transferred
* @param _data bytes optional data to send along with the call
* @return bool whether the call correctly returned the expected magic value
*/function_checkContractOnERC721Received(addressfrom,
address to,
uint256 tokenId,
bytesmemory _data
) privatereturns (bool) {
try IERC721Receiver(to).onERC721Received(_msgSender(), from, tokenId, _data) returns (bytes4 retval) {
return retval == IERC721Receiver(to).onERC721Received.selector;
} catch (bytesmemory reason) {
if (reason.length==0) {
revert TransferToNonERC721ReceiverImplementer();
} else {
assembly {
revert(add(32, reason), mload(reason))
}
}
}
}
/**
* @dev Hook that is called before a set of serially-ordered token ids are about to be transferred. This includes minting.
* And also called before burning one token.
*
* startTokenId - the first token id to be transferred
* quantity - the amount to be transferred
*
* Calling conditions:
*
* - When `from` and `to` are both non-zero, `from`'s `tokenId` will be
* transferred to `to`.
* - When `from` is zero, `tokenId` will be minted for `to`.
* - When `to` is zero, `tokenId` will be burned by `from`.
* - `from` and `to` are never both zero.
*/function_beforeTokenTransfers(addressfrom,
address to,
uint256 startTokenId,
uint256 quantity
) internalvirtual{}
/**
* @dev Hook that is called after a set of serially-ordered token ids have been transferred. This includes
* minting.
* And also called after one token has been burned.
*
* startTokenId - the first token id to be transferred
* quantity - the amount to be transferred
*
* Calling conditions:
*
* - When `from` and `to` are both non-zero, `from`'s `tokenId` has been
* transferred to `to`.
* - When `from` is zero, `tokenId` has been minted for `to`.
* - When `to` is zero, `tokenId` has been burned by `from`.
* - `from` and `to` are never both zero.
*/function_afterTokenTransfers(addressfrom,
address to,
uint256 startTokenId,
uint256 quantity
) internalvirtual{}
/**
* @dev Returns the `TokenOwnership` struct at `tokenId` without reverting.
*
* If the `tokenId` is out of bounds:
* - `addr` = `address(0)`
* - `startTimestamp` = `0`
* - `burned` = `false`
*
* If the `tokenId` is burned:
* - `addr` = `<Address of owner before token was burned>`
* - `startTimestamp` = `<Timestamp when token was burned>`
* - `burned = `true`
*
* Otherwise:
* - `addr` = `<Address of owner>`
* - `startTimestamp` = `<Timestamp of start of ownership>`
* - `burned = `false`
*/functionexplicitOwnershipOf(uint256 tokenId) publicviewreturns (TokenOwnership memory) {
TokenOwnership memory ownership;
if (tokenId < _startTokenId() || tokenId >= _currentIndex) {
return ownership;
}
ownership = _ownerships[tokenId];
if (ownership.burned) {
return ownership;
}
return _ownershipOf(tokenId);
}
/**
* @dev Returns an array of `TokenOwnership` structs at `tokenIds` in order.
* See {ERC721AQueryable-explicitOwnershipOf}
*/functionexplicitOwnershipsOf(uint256[] memory tokenIds) externalviewreturns (TokenOwnership[] memory) {
unchecked {
uint256 tokenIdsLength = tokenIds.length;
TokenOwnership[] memory ownerships =new TokenOwnership[](tokenIdsLength);
for (uint256 i; i != tokenIdsLength; ++i) {
ownerships[i] = explicitOwnershipOf(tokenIds[i]);
}
return ownerships;
}
}
/**
* @dev Returns an array of token IDs owned by `owner`,
* in the range [`start`, `stop`)
* (i.e. `start <= tokenId < stop`).
*
* This function allows for tokens to be queried if the collection
* grows too big for a single call of {ERC721AQueryable-tokensOfOwner}.
*
* Requirements:
*
* - `start` < `stop`
*/functiontokensOfOwnerIn(address owner,
uint256 start,
uint256 stop
) externalviewreturns (uint256[] memory) {
unchecked {
if (start >= stop) revert InvalidQueryRange();
uint256 tokenIdsIdx;
uint256 stopLimit = _currentIndex;
// Set `start = max(start, _startTokenId())`.if (start < _startTokenId()) {
start = _startTokenId();
}
// Set `stop = min(stop, _currentIndex)`.if (stop > stopLimit) {
stop = stopLimit;
}
uint256 tokenIdsMaxLength = balanceOf(owner);
// Set `tokenIdsMaxLength = min(balanceOf(owner), stop - start)`,// to cater for cases where `balanceOf(owner)` is too big.if (start < stop) {
uint256 rangeLength = stop - start;
if (rangeLength < tokenIdsMaxLength) {
tokenIdsMaxLength = rangeLength;
}
} else {
tokenIdsMaxLength =0;
}
uint256[] memory tokenIds =newuint256[](tokenIdsMaxLength);
if (tokenIdsMaxLength ==0) {
return tokenIds;
}
// We need to call `explicitOwnershipOf(start)`,// because the slot at `start` may not be initialized.
TokenOwnership memory ownership = explicitOwnershipOf(start);
address currOwnershipAddr;
// If the starting slot exists (i.e. not burned), initialize `currOwnershipAddr`.// `ownership.address` will not be zero, as `start` is clamped to the valid token ID range.if (!ownership.burned) {
currOwnershipAddr = ownership.addr;
}
for (uint256 i = start; i != stop && tokenIdsIdx != tokenIdsMaxLength; ++i) {
ownership = _ownerships[i];
if (ownership.burned) {
continue;
}
if (ownership.addr !=address(0)) {
currOwnershipAddr = ownership.addr;
}
if (currOwnershipAddr == owner) {
tokenIds[tokenIdsIdx++] = i;
}
}
// Downsize the array to fit.assembly {
mstore(tokenIds, tokenIdsIdx)
}
return tokenIds;
}
}
/**
* @dev Returns an array of token IDs owned by `owner`.
*
* This function scans the ownership mapping and is O(totalSupply) in complexity.
* It is meant to be called off-chain.
*
* See {ERC721AQueryable-tokensOfOwnerIn} for splitting the scan into
* multiple smaller scans if the collection is large enough to cause
* an out-of-gas error (10K pfp collections should be fine).
*/functiontokensOfOwner(address owner) externalviewreturns (uint256[] memory) {
unchecked {
uint256 tokenIdsIdx;
address currOwnershipAddr;
uint256 tokenIdsLength = balanceOf(owner);
uint256[] memory tokenIds =newuint256[](tokenIdsLength);
TokenOwnership memory ownership;
for (uint256 i = _startTokenId(); tokenIdsIdx != tokenIdsLength; ++i) {
ownership = _ownerships[i];
if (ownership.burned) {
continue;
}
if (ownership.addr !=address(0)) {
currOwnershipAddr = ownership.addr;
}
if (currOwnershipAddr == owner) {
tokenIds[tokenIdsIdx++] = i;
}
}
return tokenIds;
}
}
functionisOwnerOfTokens(address owner, uint256[] calldata tokenIds) externalviewreturns (bool) {
uint256 tokenIdsLength = tokenIds.length;
if (tokenIdsLength ==0) {
returnfalse;
}
uint256 tokenId = tokenIds[0];
if (_ownershipOf(tokenId).addr != owner) {
returnfalse;
}
unchecked {
for (uint256 i=1; i<tokenIdsLength; ++i) {
uint256 nextTokenId = tokenId+1;
tokenId = tokenIds[i];
// if the next tokenId in the array is part of the same token range// continue without checking ownership againif (tokenId == nextTokenId && _ownerships[nextTokenId].addr ==address(0)) {
// make sure tokenId is still within the supply limitif (tokenId >= _currentIndex) {
returnfalse;
}
continue;
}
if (_ownershipOf(tokenId).addr != owner) {
returnfalse;
}
}
}
returntrue;
}
}
Contract Source Code
File 11 of 29: IERC165.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts v4.4.0 (utils/introspection/IERC165.sol)pragmasolidity ^0.8.0;/**
* @dev Interface of the ERC165 standard, as defined in the
* https://eips.ethereum.org/EIPS/eip-165[EIP].
*
* Implementers can declare support of contract interfaces, which can then be
* queried by others ({ERC165Checker}).
*
* For an implementation, see {ERC165}.
*/interfaceIERC165{
/**
* @dev Returns true if this contract implements the interface defined by
* `interfaceId`. See the corresponding
* https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
* to learn more about how these ids are created.
*
* This function call must use less than 30 000 gas.
*/functionsupportsInterface(bytes4 interfaceId) externalviewreturns (bool);
}
Contract Source Code
File 12 of 29: IERC20.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts v4.4.0 (token/ERC20/IERC20.sol)pragmasolidity ^0.8.0;/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/interfaceIERC20{
/**
* @dev Returns the amount of tokens in existence.
*/functiontotalSupply() externalviewreturns (uint256);
/**
* @dev Returns the amount of tokens owned by `account`.
*/functionbalanceOf(address account) externalviewreturns (uint256);
/**
* @dev Moves `amount` tokens from the caller's account to `recipient`.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/functiontransfer(address recipient, uint256 amount) externalreturns (bool);
/**
* @dev Returns the remaining number of tokens that `spender` will be
* allowed to spend on behalf of `owner` through {transferFrom}. This is
* zero by default.
*
* This value changes when {approve} or {transferFrom} are called.
*/functionallowance(address owner, address spender) externalviewreturns (uint256);
/**
* @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* IMPORTANT: Beware that changing an allowance with this method brings the risk
* that someone may use both the old and the new allowance by unfortunate
* transaction ordering. One possible solution to mitigate this race
* condition is to first reduce the spender's allowance to 0 and set the
* desired value afterwards:
* https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
*
* Emits an {Approval} event.
*/functionapprove(address spender, uint256 amount) externalreturns (bool);
/**
* @dev Moves `amount` tokens from `sender` to `recipient` using the
* allowance mechanism. `amount` is then deducted from the caller's
* allowance.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/functiontransferFrom(address sender,
address recipient,
uint256 amount
) externalreturns (bool);
/**
* @dev Emitted when `value` tokens are moved from one account (`from`) to
* another (`to`).
*
* Note that `value` may be zero.
*/eventTransfer(addressindexedfrom, addressindexed to, uint256 value);
/**
* @dev Emitted when the allowance of a `spender` for an `owner` is set by
* a call to {approve}. `value` is the new allowance.
*/eventApproval(addressindexed owner, addressindexed spender, uint256 value);
}
Contract Source Code
File 13 of 29: IERC20Metadata.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts v4.4.0 (token/ERC20/extensions/IERC20Metadata.sol)pragmasolidity ^0.8.0;import"../IERC20.sol";
/**
* @dev Interface for the optional metadata functions from the ERC20 standard.
*
* _Available since v4.1._
*/interfaceIERC20MetadataisIERC20{
/**
* @dev Returns the name of the token.
*/functionname() externalviewreturns (stringmemory);
/**
* @dev Returns the symbol of the token.
*/functionsymbol() externalviewreturns (stringmemory);
/**
* @dev Returns the decimals places of the token.
*/functiondecimals() externalviewreturns (uint8);
}
Contract Source Code
File 14 of 29: IERC721.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts v4.4.0 (token/ERC721/IERC721.sol)pragmasolidity ^0.8.0;import"../../utils/introspection/IERC165.sol";
/**
* @dev Required interface of an ERC721 compliant contract.
*/interfaceIERC721isIERC165{
/**
* @dev Emitted when `tokenId` token is transferred from `from` to `to`.
*/eventTransfer(addressindexedfrom, addressindexed to, uint256indexed tokenId);
/**
* @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
*/eventApproval(addressindexed owner, addressindexed approved, uint256indexed tokenId);
/**
* @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
*/eventApprovalForAll(addressindexed owner, addressindexed operator, bool approved);
/**
* @dev Returns the number of tokens in ``owner``'s account.
*/functionbalanceOf(address owner) externalviewreturns (uint256 balance);
/**
* @dev Returns the owner of the `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/functionownerOf(uint256 tokenId) externalviewreturns (address owner);
/**
* @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
* are aware of the ERC721 protocol to prevent tokens from being forever locked.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must exist and be owned by `from`.
* - If the caller is not `from`, it must be have been allowed to move this token by either {approve} or {setApprovalForAll}.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
*
* Emits a {Transfer} event.
*/functionsafeTransferFrom(addressfrom,
address to,
uint256 tokenId
) external;
/**
* @dev Transfers `tokenId` token from `from` to `to`.
*
* WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must be owned by `from`.
* - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
*
* Emits a {Transfer} event.
*/functiontransferFrom(addressfrom,
address to,
uint256 tokenId
) external;
/**
* @dev Gives permission to `to` to transfer `tokenId` token to another account.
* The approval is cleared when the token is transferred.
*
* Only a single account can be approved at a time, so approving the zero address clears previous approvals.
*
* Requirements:
*
* - The caller must own the token or be an approved operator.
* - `tokenId` must exist.
*
* Emits an {Approval} event.
*/functionapprove(address to, uint256 tokenId) external;
/**
* @dev Returns the account approved for `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/functiongetApproved(uint256 tokenId) externalviewreturns (address operator);
/**
* @dev Approve or remove `operator` as an operator for the caller.
* Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
*
* Requirements:
*
* - The `operator` cannot be the caller.
*
* Emits an {ApprovalForAll} event.
*/functionsetApprovalForAll(address operator, bool _approved) external;
/**
* @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
*
* See {setApprovalForAll}
*/functionisApprovedForAll(address owner, address operator) externalviewreturns (bool);
/**
* @dev Safely transfers `tokenId` token from `from` to `to`.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must exist and be owned by `from`.
* - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
*
* Emits a {Transfer} event.
*/functionsafeTransferFrom(addressfrom,
address to,
uint256 tokenId,
bytescalldata data
) external;
}
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts v4.4.0 (token/ERC721/IERC721Receiver.sol)pragmasolidity ^0.8.0;/**
* @title ERC721 token receiver interface
* @dev Interface for any contract that wants to support safeTransfers
* from ERC721 asset contracts.
*/interfaceIERC721Receiver{
/**
* @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom}
* by `operator` from `from`, this function is called.
*
* It must return its Solidity selector to confirm the token transfer.
* If any other value is returned or the interface is not implemented by the recipient, the transfer will be reverted.
*
* The selector can be obtained in Solidity with `IERC721.onERC721Received.selector`.
*/functiononERC721Received(address operator,
addressfrom,
uint256 tokenId,
bytescalldata data
) externalreturns (bytes4);
}
// SPDX-License-Identifier: MITpragmasolidity ^0.8.0;import {SafeMath} from"@openzeppelin/contracts/utils/math/SafeMath.sol";
import {EIP712Base} from"./EIP712Base.sol";
contractNativeMetaTransactionisEIP712Base{
usingSafeMathforuint256;
bytes32privateconstant META_TRANSACTION_TYPEHASH =keccak256(
bytes(
"MetaTransaction(uint256 nonce,address from,bytes functionSignature)"
)
);
eventMetaTransactionExecuted(address userAddress,
addresspayable relayerAddress,
bytes functionSignature
);
mapping(address=>uint256) nonces;
/*
* Meta transaction structure.
* No point of including value field here as if user is doing value transfer then he has the funds to pay for gas
* He should call the desired function directly in that case.
*/structMetaTransaction {
uint256 nonce;
addressfrom;
bytes functionSignature;
}
functionexecuteMetaTransaction(address userAddress,
bytesmemory functionSignature,
bytes32 sigR,
bytes32 sigS,
uint8 sigV
) publicpayablereturns (bytesmemory) {
MetaTransaction memory metaTx = MetaTransaction({
nonce: nonces[userAddress],
from: userAddress,
functionSignature: functionSignature
});
require(
verify(userAddress, metaTx, sigR, sigS, sigV),
"Signer and signature do not match"
);
// increase nonce for user (to avoid re-use)
nonces[userAddress] = nonces[userAddress].add(1);
emit MetaTransactionExecuted(
userAddress,
payable(msg.sender),
functionSignature
);
// Append userAddress and relayer address at the end to extract it from calling context
(bool success, bytesmemory returnData) =address(this).call(
abi.encodePacked(functionSignature, userAddress)
);
require(success, "Function call not successful");
return returnData;
}
functionhashMetaTransaction(MetaTransaction memory metaTx)
internalpurereturns (bytes32)
{
returnkeccak256(
abi.encode(
META_TRANSACTION_TYPEHASH,
metaTx.nonce,
metaTx.from,
keccak256(metaTx.functionSignature)
)
);
}
functiongetNonce(address user) publicviewreturns (uint256 nonce) {
nonce = nonces[user];
}
functionverify(address signer,
MetaTransaction memory metaTx,
bytes32 sigR,
bytes32 sigS,
uint8 sigV
) internalviewreturns (bool) {
require(signer !=address(0), "NativeMetaTransaction: INVALID_SIGNER");
return
signer ==ecrecover(
toTypedMessageHash(hashMetaTransaction(metaTx)),
sigV,
sigR,
sigS
);
}
}
Contract Source Code
File 27 of 29: Ownable.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts v4.4.0 (access/Ownable.sol)pragmasolidity ^0.8.0;import"../utils/Context.sol";
/**
* @dev Contract module which provides a basic access control mechanism, where
* there is an account (an owner) that can be granted exclusive access to
* specific functions.
*
* By default, the owner account will be the one that deploys the contract. This
* can later be changed with {transferOwnership}.
*
* This module is used through inheritance. It will make available the modifier
* `onlyOwner`, which can be applied to your functions to restrict their use to
* the owner.
*/abstractcontractOwnableisContext{
addressprivate _owner;
eventOwnershipTransferred(addressindexed previousOwner, addressindexed newOwner);
/**
* @dev Initializes the contract setting the deployer as the initial owner.
*/constructor() {
_transferOwnership(_msgSender());
}
/**
* @dev Returns the address of the current owner.
*/functionowner() publicviewvirtualreturns (address) {
return _owner;
}
/**
* @dev Throws if called by any account other than the owner.
*/modifieronlyOwner() {
require(owner() == _msgSender(), "Ownable: caller is not the owner");
_;
}
/**
* @dev Leaves the contract without owner. It will not be possible to call
* `onlyOwner` functions anymore. Can only be called by the current owner.
*
* NOTE: Renouncing ownership will leave the contract without an owner,
* thereby removing any functionality that is only available to the owner.
*/functionrenounceOwnership() publicvirtualonlyOwner{
_transferOwnership(address(0));
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Can only be called by the current owner.
*/functiontransferOwnership(address newOwner) publicvirtualonlyOwner{
require(newOwner !=address(0), "Ownable: new owner is the zero address");
_transferOwnership(newOwner);
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Internal function without access restriction.
*/function_transferOwnership(address newOwner) internalvirtual{
address oldOwner = _owner;
_owner = newOwner;
emit OwnershipTransferred(oldOwner, newOwner);
}
}
Contract Source Code
File 28 of 29: SafeMath.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts v4.4.0 (utils/math/SafeMath.sol)pragmasolidity ^0.8.0;// CAUTION// This version of SafeMath should only be used with Solidity 0.8 or later,// because it relies on the compiler's built in overflow checks./**
* @dev Wrappers over Solidity's arithmetic operations.
*
* NOTE: `SafeMath` is generally not needed starting with Solidity 0.8, since the compiler
* now has built in overflow checking.
*/librarySafeMath{
/**
* @dev Returns the addition of two unsigned integers, with an overflow flag.
*
* _Available since v3.4._
*/functiontryAdd(uint256 a, uint256 b) internalpurereturns (bool, uint256) {
unchecked {
uint256 c = a + b;
if (c < a) return (false, 0);
return (true, c);
}
}
/**
* @dev Returns the substraction of two unsigned integers, with an overflow flag.
*
* _Available since v3.4._
*/functiontrySub(uint256 a, uint256 b) internalpurereturns (bool, uint256) {
unchecked {
if (b > a) return (false, 0);
return (true, a - b);
}
}
/**
* @dev Returns the multiplication of two unsigned integers, with an overflow flag.
*
* _Available since v3.4._
*/functiontryMul(uint256 a, uint256 b) internalpurereturns (bool, uint256) {
unchecked {
// Gas optimization: this is cheaper than requiring 'a' not being zero, but the// benefit is lost if 'b' is also tested.// See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522if (a ==0) return (true, 0);
uint256 c = a * b;
if (c / a != b) return (false, 0);
return (true, c);
}
}
/**
* @dev Returns the division of two unsigned integers, with a division by zero flag.
*
* _Available since v3.4._
*/functiontryDiv(uint256 a, uint256 b) internalpurereturns (bool, uint256) {
unchecked {
if (b ==0) return (false, 0);
return (true, a / b);
}
}
/**
* @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
*
* _Available since v3.4._
*/functiontryMod(uint256 a, uint256 b) internalpurereturns (bool, uint256) {
unchecked {
if (b ==0) return (false, 0);
return (true, a % b);
}
}
/**
* @dev Returns the addition of two unsigned integers, reverting on
* overflow.
*
* Counterpart to Solidity's `+` operator.
*
* Requirements:
*
* - Addition cannot overflow.
*/functionadd(uint256 a, uint256 b) internalpurereturns (uint256) {
return a + b;
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting on
* overflow (when the result is negative).
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
*
* - Subtraction cannot overflow.
*/functionsub(uint256 a, uint256 b) internalpurereturns (uint256) {
return a - b;
}
/**
* @dev Returns the multiplication of two unsigned integers, reverting on
* overflow.
*
* Counterpart to Solidity's `*` operator.
*
* Requirements:
*
* - Multiplication cannot overflow.
*/functionmul(uint256 a, uint256 b) internalpurereturns (uint256) {
return a * b;
}
/**
* @dev Returns the integer division of two unsigned integers, reverting on
* division by zero. The result is rounded towards zero.
*
* Counterpart to Solidity's `/` operator.
*
* Requirements:
*
* - The divisor cannot be zero.
*/functiondiv(uint256 a, uint256 b) internalpurereturns (uint256) {
return a / b;
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* reverting when dividing by zero.
*
* Counterpart to Solidity's `%` operator. This function uses a `revert`
* opcode (which leaves remaining gas untouched) while Solidity uses an
* invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/functionmod(uint256 a, uint256 b) internalpurereturns (uint256) {
return a % b;
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting with custom message on
* overflow (when the result is negative).
*
* CAUTION: This function is deprecated because it requires allocating memory for the error
* message unnecessarily. For custom revert reasons use {trySub}.
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
*
* - Subtraction cannot overflow.
*/functionsub(uint256 a,
uint256 b,
stringmemory errorMessage
) internalpurereturns (uint256) {
unchecked {
require(b <= a, errorMessage);
return a - b;
}
}
/**
* @dev Returns the integer division of two unsigned integers, reverting with custom message on
* division by zero. The result is rounded towards zero.
*
* Counterpart to Solidity's `/` operator. Note: this function uses a
* `revert` opcode (which leaves remaining gas untouched) while Solidity
* uses an invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/functiondiv(uint256 a,
uint256 b,
stringmemory errorMessage
) internalpurereturns (uint256) {
unchecked {
require(b >0, errorMessage);
return a / b;
}
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* reverting with custom message when dividing by zero.
*
* CAUTION: This function is deprecated because it requires allocating memory for the error
* message unnecessarily. For custom revert reasons use {tryMod}.
*
* Counterpart to Solidity's `%` operator. This function uses a `revert`
* opcode (which leaves remaining gas untouched) while Solidity uses an
* invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/functionmod(uint256 a,
uint256 b,
stringmemory errorMessage
) internalpurereturns (uint256) {
unchecked {
require(b >0, errorMessage);
return a % b;
}
}
}
Contract Source Code
File 29 of 29: Strings.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts v4.4.0 (utils/Strings.sol)pragmasolidity ^0.8.0;/**
* @dev String operations.
*/libraryStrings{
bytes16privateconstant _HEX_SYMBOLS ="0123456789abcdef";
/**
* @dev Converts a `uint256` to its ASCII `string` decimal representation.
*/functiontoString(uint256 value) internalpurereturns (stringmemory) {
// Inspired by OraclizeAPI's implementation - MIT licence// https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.solif (value ==0) {
return"0";
}
uint256 temp = value;
uint256 digits;
while (temp !=0) {
digits++;
temp /=10;
}
bytesmemory buffer =newbytes(digits);
while (value !=0) {
digits -=1;
buffer[digits] =bytes1(uint8(48+uint256(value %10)));
value /=10;
}
returnstring(buffer);
}
/**
* @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
*/functiontoHexString(uint256 value) internalpurereturns (stringmemory) {
if (value ==0) {
return"0x00";
}
uint256 temp = value;
uint256 length =0;
while (temp !=0) {
length++;
temp >>=8;
}
return toHexString(value, length);
}
/**
* @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
*/functiontoHexString(uint256 value, uint256 length) internalpurereturns (stringmemory) {
bytesmemory buffer =newbytes(2* length +2);
buffer[0] ="0";
buffer[1] ="x";
for (uint256 i =2* length +1; i >1; --i) {
buffer[i] = _HEX_SYMBOLS[value &0xf];
value >>=4;
}
require(value ==0, "Strings: hex length insufficient");
returnstring(buffer);
}
}